Most of us understand that a hologram is a projected three-dimensional image made up of beams of light. If you put your hand up to a hologram, it’ll pass straight through. Now, a team of Japansese researchers have devised a way to give a hologram a “surface” that you can feel when it touches your hand. The result are holograms that you can actually interact with using your hand, and can feel when you “touch” them.

The researchers, led by Professor Hiroyuki Shinoda of Tokyo University, have devised a projector that not only displays the hologram in open space, but also includes a pair of Nintendo Wii controllers that can sense motion and the position of your hand in the field where the hologram is being projected. That way the computer controlling the hologram knows where your hand is when you interact with it.

They also built an array of computer-controlled ultrasonic wave emitters with fine points that, when the hologram lands on the surface of your hand, emit pulses of air that feel like pressure on your hand. This way the system knows where your hand is, and when the hologram touches your hand, the ultrasonic waves make your hand feel like an object is there. It doesn’t create the sensation of weight or heft, but a prolonged or more powerful burst can indicate a “heavier” hologram.

So far, the technology has only been used for simple objects, like a “ball” bouncing off the surface of your palm, or “raindrops” falling onto your hand or arm. The researchers plan to extend the technology to create interfaces that provide haptic feedback but are actually entirely made of light. For example, Professor Shinoda says you can easily use these holograms to replace light switches in hospitals, which are sometimes the source of contamination because they’re shared by so many people.

The Star Trek Emergency Medical Hologram lives. On Star Trek they used force fields to create resistance and the sensation of touch. It also allowed the hologram to pick up and manipulate objects. In short, anything a human could do it could do. It even had sexual relations.